# Seven

Seven friends agree to send everyone a holiday card. How many postcards were sent?

**Result****Leave us a comment of example and its solution (i.e. if it is still somewhat unclear...):**

**Showing 0 comments:**

**Be the first to comment!**

#### To solve this example are needed these knowledge from mathematics:

## Next similar examples:

- Sweater

Dana confuses sweater and wool has a choice of seven colors. In how many ways she can choose from three colors to the sleeves? - Seven-segmet

Lenka is amused that he punched a calculator (seven-segment display) numbers and used only digits 2 to 9. Some numbers have the property that their image in the axial or central symmetry was again give some number. Determine the maximum number of three-d - Logik game

Letter game Logik is a two player game, which has the following rules: 1. The first player thinks five-letter word in which no letter is not repeated. 2. The second player writes a five-letter word. 3. The first player answers two numbers - the first numbe - The percentages in practice

If every tenth apple on the tree is rotten it can be expressed by percentages: 10% of the apples on the tree is rotten. Tell percent using the following information: a. in June rained 6 days b, increase worker pay 500 euros to 50 euros c, grabbed 21 fro - Pins 2

how many different possible 4 digits pins can be found on the 10-digit keypad? - Factory

In the factory workers work in three shifts. In the first inning operates half of all employees in the second inning and a third in the third inning 200 employees. How many employees work at the factory? - Chess

How many different ways can initiate a game of chess (first pass)? - Sales off

Goods is worth € 70 and the price of goods fell two weeks in a row by 10%. How many % decreased overall? - Percents - easy

How many percent is 432 out of 434? - Apples 2

James has 13 apples. He has 30 percent more apples than Sam. How many apples has Sam? - Pipe

Steel pipe has a length 2.5 meters. About how many decimetres is 1/3 less than 4/8 of this steel pipe? - Three digits number 2

Find the number of all three-digit positive integers that can be put together from digits 1,2,3,4 and which are subject to the same time has the following conditions: on one positions is one of the numbers 1,3,4, on the place of hundreds 4 or 2. - TVs

Production of television sets increased from 3,500 units to 4,200 units. Calculate the percentage of production increase. - Inequation

Solve the inequation: 5k - (7k - 1)≤ 2/5 . (5-k)-2 - Gloves

I have a box with two hundred pieces of gloves in total, split into ten parcels of twenty pieces, and I sell three parcels. What percent of the total amount I sold? - Number

What number is 20 % smaller than the number 198? - Equation

Solve the equation: 1/2-2/8 = 1/10; Write the result as a decimal number.